Abstract: Acetaldehyde dehydrogenase (ALDH) was isolated and purified by the Acetobacter pomorum obtained from the self-screening of the laboratory, cell disruption, ammonium sulfate fractionation, DEAE-Sepharose fast flow chromatography and Superdex G-75 prep grade chromatography separation and purification of enzyme liquid aldehyde dehydrogenase, and its enzymatic properties was studied.The molecular weight of the enzyme was 221.60 kDa, in which the subunit molecular mass was 54.41 kDa, respectively. The crude enzyme was purified 10.16 times with 20.25 U/mg of enzyme activity and the recovery rate of ALDH was 6.53%. The enzyme properties showed that its optimal reaction temperature was 50℃, and the enzyme had a good stability between 40℃ and 50℃;The optimal reaction pH of ALDH was 7.0, and there was a good stability between pH5.5 and pH7.5. The effects of different metal ions on enzyme activity showed that the enzyme was strongly inhibited by Na⁺, K⁺, Zn²⁺, Ba²⁺, however, Mg²⁺、Ca²⁺、Al³⁺、Li⁺、Cu²⁺ activated the enzyme activity. The substrate specificity of ALDH showed that the enzyme had higher enzyme activity on acetaldehyde, which was on straight aldehydes. ALDH had high enzyme activity, which provided a foundation for further investigation of biological function.